Carburetor



v CARBURE'IORl 4 Sheets-Sheet.4 1

Original Filed feb. 5, 1955 @van fors." fyi/(022 JZLe-f 62 maf/@24.

4 Sheets-Shset 2 CARBURETOR original Filqd Feb. 5, 1935 1v- 'JI/'. fr

` M. E. CHANDLER ETAL Aprilfzz.,i 1941.

April 22, 1941. M ?a CHANDLER Erm. Re' 21,774

` A JARBURETOR Original Filed Feb. 5,l 1955 4 Sheets-Sheet 5 I zz/ effam' AZZ/fof? rf .Kaff/ef (9M/f@ f aza//ef I #556mg April 22, 1941. l M. E. CHAIJDLER ETAL R'e.A 21,774

CARBURETOR Original Filed Feb. 5, 1935 v 4 Sheets-Sheet 4;

Ressued Apr. 22, 1941 UNITEDISTATBS PATENT OFFICE.

CABBUEETOB Milton E. Kittler,

chandler, nil-minnen, ma Milam' J. Detroit, Mich., asaignors, by direct and mesnc assignments; to Chandler-Evans Corporation.

Meriden, Conn., a corporation of Delaf origini No. 2,998,464, ama nu; a1. i991, serial No. 5,144, February 5, 1985.

Application for reissue May 29, 1939, serial No. 2115.444

(ci. 2in-12) 4 Claims.

This invention relates to carburetlon devicesy and, more particularly. to carburetors and related apparatuses having features of such'character as to make the devices and apparatuses peculiarly suitable for aircraft engines although it is .not`

limited to such field of use.

A One of the primary' objects of the invention is to provide an arrangement of fuelsupply and control apparatus for carburetion purposes n. wherein the fuel supplied under pressure i'romY a source, such as through a fuel pump, may be controlled to provide the necessary amount offuel at the times desired, the control being effective through mechanisms affected by atmospheric .pressure variations and variations in pressure of iiuids (fuel and air) passing into or through the apparatus during the functioning of the appar- `atus. Y

' Another important object is to provide a novel arrangement wherein fuel supplied under pressure from a fuel pump `or otherwise, is admitted to a fuel chamber of variable capacity and delivered from said chamber into the air or mixture passage leading tothe intake of the engine, under controls automatically determined by varying factors incident to the engine operation and to the air supplied to the carburetor for fuel mixture purposes.

Another of the objects of this invention is to i design a variable Venturi carburetor suitable for 2L aircraft engines of the internal combustion type having external carburetor means. Many other objects as well as the advantages and uses of the invention win be or should ue-` come apparent as this description proceeds.

The ordinary aircraft carburetor has been designed as `a modied automobile carburetor in which the production requirements havev been a factor. Byy departing from the accepted design and placing the fuel nozzle on the engine side of v the throttle and utilizing the throttle means to provide a variable Venturipassage around the a part of the mechanism shown in either Figs. -1`

and 2 or FigsA-and 5 together with an automatic altitude control, the diagram also generally representing the mechanism for controlling the supply of fuel into a variable "capacity fuel chamber designated 63.

Figure 'l shows a manual altitude control torbe used as an alternative control with the construction shown in Figure 6.

` Figure 8 shows diagrammatically the method for providing hot air tothe throttles. v

Figure 9 shows another alternative method of heating the throttle.

Figure 10 shows diagrammatically the arrangements of the throttles showing the outlets for the heated air.

Figure 1l shows an alternative outlet for the These end plates 40 and 4I are bolted together fuel nozzle the maximum degree of atomization is secured without the danger offreezing,

f By making the carburetor of fiat pieces bolted tbgether the scrap loss dueto porous castings is reduced and the cost o f manufacturing Vthese large carburetor castings is greatly'reduced. A special problem has been given a specic solution:

Figure 1* shows a planview of the preferred form of construction.

- Figure 2 shows a cross-section elevation taken on plane 2--2 of Figure l.

l 4 Figure .3 shows the detail ing manifolds t0 the throttles.

'of clamping the heatby means of thethrough bolts 45, 46, 41, and 48. Located in the mixing chamber 44 are two similarrhollow throttles 49 and 5U. These two throttles are geared together in a well known manner, The pitch-lines of the gears are shown diagrammatically by the circles 90 and 9| Figure 2 and the gears in full lines in Figure i4, in which figure the throttles 49 and 5l are shown diagrammatically.

In Figures 1 and 2, 5i 4is a vertical fuel passage 4which leads to a second fuel passage 52 which extends transversely across the mixing chamber 44 and with which the two hollow throttles 49 and 5I are adapted to engage. It will be obvious that as the throttles open rectangular slots are opened between 52 and the throttles 49 and l0. Fuel outlets 53 and 54 are arranged to discharge along the center of the ltwo narrow slots thus formed.

The streamlined surfaces'of 49 and 5I thus form a' variable Venturi passage for the air. The wall of may be. .through these manifolds: hot air,v exhat l vtlecont'rx'rlImltedtoaahaitllw throttle ismolmted Y cant, the throttles 4l and). andvthe needl l .Ilareallrnovedinunisom the Aair entrance to the carburetor is numbered Gearedto thethrottlesan'dllisagear Il (Figures 2 and 14) vwhich meshes with the gear Il. Thegear llop'eratesacam (Figure 2) which engages witharollerilmoimtedon elever u plvenymehoredet tummeln casting 43. This lever Il engages with a needle Il which controls the fuel restriction Il in a main fuel passage I2. This fuel is supplied from a fuel supply chamber t! which is formed between two'exiblediaphragms I4 and Il, the fuel being supplied to this chamber through an inlet connection passage III connected (see Fig. 6) through a pipe lil with a fuel pump i-l1. An

. automatic air pump is formed by means of two inter-communicating air chambers 1l and 11 in effect surrounding this 'fuel chamber This air.

passageataplacebackofthethrottleltandso. is in communication with the mixing chamber 44 so that lthe engine suctionl acts on the dia- Dhragm l.. In order to insure that-this is so. a wiper 1l engages withthecircularcylindrical sur- 'faceofthethrottlell Asimilarlpel'block" emes with. the throttle bl, 'thus sealing the mixing chamber from the air entrance 1I. Endleakageislimitedbyrectangularmeces shown in broken lines'at III-itl Figures. Y A restricted air vent 14 communicates with the atmosphere at a place adiacent to the air and mixture through thecarburetor anti also communicates with'the air chamber 1l fonned between the diaphragm andthe diaphragm 'l.-'1herestritedairpassage14a1so communicatesthmughapassagelitotheother.

air chamber 11A `formed between'tm diaphragm I4 and a cover 1l. Passage IQ thereforeprovldes communication between air chambers 11 and 1l and between these chambers andthe eemeen wnienmsenergeeelraneeuy Inordertoadmitheatintotheinterlorof the hollow throttles Il and. Il two manifolds provided-83 and.v (See'also Figure 14.) of' the following heating means hot oil, or hot ll and Il are which apre'ssure onthe manifolds and 04. Bridges. and" areprovided so the manifolds'ljand 'may be held tightly egeinst the mmttlee uf mi. u: shown in Figure3;

thegear YHainich-'engages with Y through the'gear SI with a gear llupon which By this means a mnguresrandsamethoucfemn'ouingme InFigure'Ialternativemanual-meansisshown l A -for controlling thepresaure and showss ooredoastings are used.

e. a' chamber tically the preferred method cf conwhich is by means of aneroid bellows III. In this figure a fuel pump H1 is shown which obtains-fuel from a pipe' ill and discharges its fuel through aplpe l la pastthe two neeme veuves Ill and l'il. Theseneedle valves are connected by levees` m ena ,in plveted et -m end m' and theY levers are-connected with the diaphragme se emi- 11u et m' end In, respectively. ceu springs!" and |251 are used'to support the dia? p 64 and 65 and areA located in chambers 1l and-11. The compression in these springs is controlled b'y the movement of the bellows III which is responsive to atmospheric pressure. Linkage Ill, |21 and |20 transmits the movement of the bellows IIB so that the compression in the springs |25 and |284 is varied as the altitude varies. In the fuel outlet 62 the restriction 8l and the needle valve are as shown in Figure 2. We have discovered thatthe use of twov diaphragms and two valves enables us to deliver l seven hundred pounds of gasoline per hour at three or four pounds pressure per square in ch and to withstand a pressure in the fuel pump.

of twenty pounds per square inch. The use of a single diaphragm anda single valve requires them both to be excessively large." ,v

5 Figure 'I showifa manually ,operated lever III" adaptedto be connected through linkage i20'.-

|121' withrthe spring Ill'.

In Figure 8 an exhaust pipe |40 is shown pass- A ing through the center of a heat eichanger. .lll in which are located a large number of fins |42 mounted o n the exhaust pipe |49. A n air ientrance |43 admits air to flow over these ilns. An outlet |44 admits air to the hollow -throttles 49 and Il through the manifold ,A the manifold I4 providing the outlet (see Figures l and 4). Means (not shown) :are provided for drawing the air out of. i A

In Figures 9, 1o, and 11 the ouueffmenueld Tu is with and the hot air `escapes through l" and I formed in the hollow throttl II and 'il either-on the up stream side Figure l0) or the down stream side (Figure 11) of the throttles.

admitted through a Y'passagefill located lbelow the fuel e i2 from'which the fuel discharges through outlets-'53.

Figures 14 and 15 show diagrammatically two hollow throttles' 4l and Il. which` are connected 'with the end manifolds Il and I4, which admit .nm te the interior ef me ulrottlee.l

Gear wheels il. I and II -are also shown wherelevier'Il,showninliigure2.v

. Figures 4 and 'show how the central portion 4 3 of ligure 2 can be divided in two parts,- 4I". connected by 'a separate v cross piece. III.'

which contains the fuel needle fuelrestric# "tien al pesage sa? Benen te this crees piece ltlis the casting i. containing theii'uel mes Il and I! out o f'which lead the fuel u. 'The differenterewritingA from this as the construction Figures 1 and 2 is that lno coredcastings are and the production of solid cast-V i'rom-blow holesiis much easier to .con-

trol with such solid castings than'is the case when -In Figures 12 and`l3 some heating medium is n '.cam' topermit more or less fuelto flow past the restriction si, through the :nel openings n and il, into the throat of the variable venturi.

formed betweenfthe throttles 48 and Il, and so into the mixture outlet Il. When the throttle is opened suddenly the low pressure in Il is broken. The pressure in Il therefore rises and the flexible wall moves to the left under the influence of the'sprlng I1. The flexible wall Bl then moves t over to the left andthe pressure in the constant pressure fuell supply chamber 8l is temporarily` raised above the normal pressure which of course depends on the elastic flexibility'of the wall il. The flow through Il is thus temporarily increased during the acceleration period ofthe engine. By making 14 very small this action is prolonged for a definite period of time and by making, 1l very Ilarge this action ia negligible. hence 1I can be made exactly the right size to give the desired perfomance. I

lThe operation of the other figures will `be obvious from their description, except that in Figure 6 an increase in atmospheric pressure will compress the springs I2l-Il5' and a decrease in atmospheric pressure will expand the bellows Hi and thus relieve the springs lll-III' and s thus decrease the pressure of the fuel delivered through, Hence, as the airplane climbs the Y mixture ratio is maintained constant.

By means of the arrangement ofdiaphragme shown tothe left of Iligin'e 2.and diagrammatically in'Figure 6*., the carburetor is rendered less sensitive to stunting. .When the inertia eifects move 'from right to left in Figure 6. for

example, needle valle lllls shut of, but the 6 the plane to maneuver is not interfered with.

We claim:

l. A fuel simply means for an `aviation carburetor comprising, a fuel pump. a fuelpassage leading therefrom. a fuel supply chamber having l0 a flexible wallI a fuel outlet from said chamber,

an inlet valve for controlling fuel discharge into said chamber from `-said -fuel e, said valve being operated by said flexible wall. spring means for supporting said wall. and means responsive 15 to variation in atmospheric pressure for varying the compression of said spring means. 2. A fuel supply means for an aviation carburetor comprising. a source of fuel under pressure, a .fuel passage leading therefrom. a fuel 2o.supply chamber having a connection with said fuel passage and having a flexible wall. la. fuel outlet from said chamber, an inlet valve for con trolling discharge into said chamber from said fuel passage, said valve being operated by said 25 flexible-wall, spring means for supporting -said wall, and` means responsive to variation in atmospheric pressure for varying the effect of said spring means. f

3. Heating means for a carburetor comprising,

ao two hollow throttles adapted to roll together to Vform a variable venturi. a fuel nozzle 'discharging between said throttles. means for circulating a heating fluid through said hollow throttles, ad-

ditional heating means comprising a heating as passage having an axis parallel to that of the lthrottles and located centrally therebetween, said 1 fuel nozzle being associated with said heating passage so as to be heated thereby.

4.' Heating means as described in claim 3 in 0 which the additional heating means is located on the down stream side of said nozzle so as tol form a stream-lining contour thereby.l

, MILTON E. CHANDLER.

MIHI'ON J. KII'I'LERW 

